This one can be difficult. Everyone has good acvice and different things that work for them but its really up to the snake.. My ICH for instance.. Was started on live and i kept her on live for a few years because she was always a picky eater. For her everything was based on size, color, smell, temperature etc..

I eventually got her on fresh prekilled (humainly) but she still sometimes will not take a F/T unless its very warm, dark in color, not too big, and she is definately a tease-eater.. To get her on the prekilled it took me offering her nothing but that for over 2 months. Once a week she was offered. when she did not take it, I put it in the freezer to trade for another the following week. She eventually got hungry enough and i learned her preferences and how to make the rat move like its alive.

Now she takes F/T occaisionally but still prefers the freshest over the frozen.